DISEASE CHARACTERISTICS: Histologically or cytologically confirmed non-small cell lung cancer (NSCLC) Stage IIIB or IV Newly diagnosed or recurrent disease Measurable lesions At least 10 mm by spiral CT scan OR At least 20 mm by conventional techniques Previously irradiated lesions are considered measurable provided they progressed or appeared after completion of radiotherapy The following are considered nonmeasurable: Pleural or pericardial effusions Cystic lesions Lymphangitis pulmonis Bony x-ray abnormalities Abnormal scans with nonmeasurable filling defects No symptomatic brain metastasis or CNS involvement by CT scan or MRI